Tuning device



July 4, 1950 D. J. DICKERSON 2,514,153

TUNING DEVICE Filed March 22. 1948 V fiELBERT (I DICKERSON INVENTOR.

A TTOQNE Y.

Patented July 4, 1950 TUNING DEVICE .Delbert J. Dickerson, Agoura, Calif., assignor of one-half to Arthur B. McMahan, Long Beach,

Calif.

Application March 22, 1948, Serial No. 16,209

2 Claims.

. This invention has to do with improved devices fortuning musical instruments and particularly with devices of the type in which a visual indication of correct tuning is given to the operator.

Most tuning methods require that the tuner determine audibly when the pitch of a tone emanating from the instrument corresponds exactly with that of a tone of known pitch. This necessarily requires a high degree of skill in differentiating between closely similar tones. To eliminate the requirement of such skill, it is desirable to employ a tuning instrument in which a visual indication of the correct setting is given. The main object of the present invention is to provide such a visual tuning device, so designed as to be easily adjustable to successively tune the various pitches (e. g., string pitches) of a musical instrument.

It has heretofore been suggested that a tightly drawn string of adjustable eifective length be employed to visually indicate correct tuning by its sympathetic vibration with a tone of predetermined pitch. However, because of the difliculty of perceiving the minute vibrations of such a string, that type device is not as satisfactory as might be desired. In order to overcome this difficulty and achieve certain other advantages, the present invention uses a reed having a free end sympathetically vibratable in response to the sounding of a musical tone. To provide for adjustability to various pitches, the invention may include means for varying the eifective vibratable length of the reed to thereby Vary the pitch at which the reed will sympathetically vibrate.

The reed preferably comprises a resilient wirelike member, which may be slidably retained within a frictional clamp in order that its relative positioning within the clamp will determine the length of the reed remaining free to vibrate at any particular setting. The device includes means indicating to the operator the exact pitch to which the reed has been set. Desirably, this pitch indication is shown on a graduated rule movable with the reed.

It is a further object of the invention to provide a novel housing for the tuning device, designed to effectively protect the reed assembly from accidental damage, while permitting clear viewing of the vibrating reed and of the graduated rule. This object is best achieved by the use of an elongated hollow housing having an internal mounting clamp to support the reed assembly for longitudinal movement within the housing. Sight openings are provided for viewing the reed and rule. The housing may bear indicating means, such as a pointer situated in proximity to the rule, to show precisely the exact reed setting.

The above and further features and objects of the present invention will be better understood from the following detailed description of the typical embodiment illustrated by the accompanying drawing, in which:

Fig. 1 is a plan view of the preferred form of adjustable tuning instrument;

Fig. 2 is a longitudinal Vertical section of the instrument taken on line 2--2 of Fig. 1;

Fig. 3 is a transverse vertical section taken on line 33 of Fig. 2; and

Fig. 4 is a plan view of the reed assembly removed from the housing.

The tuning instrument comprises a housing III, a reed assembly, generally indicated at II and shown removed from the housing in Fig. 4, a clamp I2 for slidably retaining the reed assembly within the housing, and a detent pointer I3 for indicating and maintaining the position of the reed assembly relative to the housing.

The housing consists of a cylindrical portion III and a flattened end portion I5. Legs I5 project from the under side of portion I4 to permit resting of the housing upon any suitable surface.

Clamp I2 is secured, as by screw IT, in an upwardly extending position within cylindrical portion Id of the housing near its juncture with portion I3. The clamp is vertically split at I8, see Fig. 3, and contains a small opening I9.

The reed assembly comprises a resilient wirelike reed 20 secured at one end to rule 2|, which is graduated to indicate the various tone pitches within a predetermined range. The rule is typically represented in Fig. 4 as covering one octave. The surface of extremity 22 of rule 2I is knurled, as illustrated, to provide a grip or handle for easily moving the reed assembly relative to housing I0. Reed 20 is slidably received within opening I9 of clamp I2 and is frictionally retained by the clamp in any longitudinal position to which it may be set by manipulation of handle 22.

Pointer I3 is secured to the enlarged portion I4 of the housing, as by screw 23, and extends through opening 24 in the reduced portion of the housing to indicate on scale 2I the precise setting to which the reed assembly has been moved. The pitch markings 21 on the rule are in the forms of notches in order that the pointer may have a detent action to maintain the reed assembly in any position to which it may be set. To render the pointer eifective for this purpose, it is made of a resilient material, such as spring steel.

3 Slot 25 at the attached end of the pointer permits adjustment of the pointer to assure correct indications of pitch on the rule. Opening 26 in the housing is provided to allow the operator to view reed 20 in order to visually determine when its point of maximum vibration is reached.

In operation, the reed assembly is first moved longitudinally of the housing by handle 22 until pointer l3 indicates the desired pitch on rule 25. The pitch of the corresponding note on the musical instrument is then adjusted to the point at which its sounding induces maximum sympathetic vibration of reed 20, as observed through opening 28. When this point of maximum vibration is achieved, the particular note on the instrument is correctly tuned, and the same process may then be employed to similarly tune the other notes on the instrument to their respective pitches.

I claim:

1. An adjustable tuning instrument of the character described, comprising a body a vibratable reed carried by the body and having a free end enclosed therein, means slidably supporting said reed for vibration of its free end in response to the sounding of a musical tone, said reed being slidable relative to said supporting means to permit varying of the effective vibratable length of said reed to thereby vary the pitch at which the reed will sympathetically vibrate, said free end of the reed being spaced from the body for uninhibited vibration beyond both sides of the plane of the reed a graduated rule carried by said reed,

transverse notches on said rule acting as graduations to represent various pitches, and detent means carried by said supporting means to selectively engage the notches of said rule and thereby indicate and maintain the pitch to which said reed is set.

2. An adjustable tuning instrument of the character described, comprising a housing open at an end, a vibratable reed having a free end enclosed within said housing and movable thereon to vary the pitch at which said reed will sympathetically vibrate, said free end of the reed being spaced from the housing for uninhibited vibration beyond both sides of the plane of the reed and a handle grip carried by said reed and projecting from aid open end of the housing to permit moving of the reed to any desired setting.

DEILBERT J. DICKERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 139,912 Morgan June 17, 1873 796,289 Brady Aug. 1, 1905 FOREIGN PATENTS Number Country Date 205,560 Germany Jan. 4, 1909 377,492 Germany l- June 20, 1923 

